Harvesting machines are commonly used to sever standing crops in the field and deposit the crop back onto the ground in the form of a windrow or swath to sever. A header at the front of a windrower cuts the ripened crop from the field. The crop is transported to the rear of the header and forming shields form a windrow of the crop between the tires or tracks of the machine for natural dry down of the crop. A subsequent field operation picks up the windrows for further processing, such as separating and cleaning in the case of grain crops, or baling or chopping in the case of hay.
Platform headers and draper headers are header types commonly used when harvesting crops such as small grains, peas, lentils, and rice. When operating the header, it is desirable to have the ability to adjust the height at which the crops are cut off and also to sense and change the vertical position of the header to follow changing terrain. To accomplish this, it is known to use a header float system or a terrain following system to enable the header to follow the ground over changing terrain without gouging or digging into the soil.